Horse has thrush but needs to be turned out...??? tips on treating thrush.?

I have a medicine for thrush, but it came with my horse so I don't know where the owners got it. But it's purple and stains your clothes(I learned this the hard way) but you just put a few drops on the bottom of the horses hooves and you can also do that even if your horse dosnt have thrush and it prevents it. If you can find anything like that you should.